Hello,
For information only (reverting back to Java 8), I have got that error after having updated to Java 9
DataFolder: C:\Users\svann\AppData\Roaming\B4ASdkManager
Error: Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
at com.android.repository.api.SchemaModule$SchemaModuleVersion.<init>(SchemaModule.java:156)
at com.android.repository.api.SchemaModule.<init>(SchemaModule.java:75)
at com.android.sdklib.repository.AndroidSdkHandler.<clinit>(AndroidSdkHandler.java:81)
at com.android.sdklib.tool.SdkManagerCli.main(SdkManagerCli.java:117)
at com.android.sdklib.tool.SdkManagerCli.main(SdkManagerCli.java:93)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlSchema
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:185)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)
... 5 more
Thank you for reporting this. The error itself happens in Android SDK tools.
I will update B4A Sdk Manager to use the Java version set in B4A setting (if there is one). This will allow you to keep Java 9 and select Java 8 in B4A IDE.